Boat&#39;s davit and the raising and lowering gear therefor.



J. GRAHAM.

BOATS DAVIT AND THE RAISING AND LOWEBING GEAR THEREFOR.

APPLICATION FILED MAY 31, 1910. I 1,024,507, Patented Apr. 30, 1912.

3 SHEBTSSHEET l.

J. GRAHAM.

BOATS DAVIT AND THE RAISING AND LOWEBING GEAR THEREFOR.

APPLIUATION FILED MAY 31, 1910.

1,024,507. Patented Apr. 30, 1912' 3 SHEETSSHEET 2.

Y J. GRAHAM. BOAT'S DAVIT AND THE RAISING AND LOWERING GEAR THEREFOR.

APPLICATION FILED MAY 31, 1910.

Patented Apr. 30, 1912.

3 SHEETSSHEET 3.

mine-5.56.5:

UNITED STATES PATENT OFFICE.

JOHN GRAHAM, O-F GLASGOW, SCOTLAND.

BOATS DAVIT AND THE RAISING AND LOWERING GEAR THEREFOR.

Specification of Letters Patent.

Patented Apr. 30, 1912.

Application filed May 31, 1910. Serial No. 564,199.

To all whom it may concern:

Be it known that I, JOHN GRAHAM, a subject of the King of Great Britain,residing at Glasgow, Scotland, have invented certain new and usefulImprovements in and Connected with Boats Davits and the Raising andLowering Gear Therefor, of which the following is a specification.

This invention relates to boats davits and to the raising and loweringgear therefor. Under this invention there is provided a single davit,which turns about a vertical axis, and from which the boat is slungcentrally by a single rope, the winding gear for lowering and raisingthe boat being se cured to and carried by the davit, and means beingprovided for automatically locking the davit in the outboard loweringposition and also in the inboard position. Further, an automaticallyacting braking arrangemnt is provided for arresting the fall of the boatshould the operators leave or be washed away from their posts during theraising of the boat. Other improvements are also provided in connectionwith the davit.

In order that the invention may be clearly understood I have hereuntoappended explanatory drawings which show, by way of example, one mode ofcarrying out the invention.

On the drawings :-Figure 1 is a side view of the single davit andshowing the boat raised off the chocks ready for lowering. Fig. 2 is anenlarged view showing the locking gear. Fig. 3 is a vertical section ofthe lower end of the davit. Fig. 4 is a plan view of the lockingmechanism of the davit. Fig. 5 is a vertical section of the same. Fig. 6is a side view of the brake gear. Fig. 7 is a vertical section thereof.

In carrying out the invention the davit a is preferably made with a pairof side cheeks b which may be partially or wholly closed at the frontand receive, therebetween, the winding gear by means of which the boatis raised and lowered, the suspension rope 0 being passed over pulleys cin the davit a and around a pulley 0 The boat raising and lowering gearconsists of a winding drum (Z which is fixed on a shaft 6 and is capableof being operated, through reducing gear wheels cl ,,by means of a pairof crank handles (Z and pinions and freely mounted concentric to theintermediate shaft 6 of one of the gear wheels (Z is an internallytoothed wheel or ring 6 (see Figs. 6 and 7') having ratchet or inclinedteeth adapted to be engaged by pawls f freely pivoted on the face of adisk or wheel f which is keyed on the said intermediate shaft 6. Locatedaround the outer periphery of the said free wheel or ring 6 is a handbrake 9 one end of which is secured, at 9 to the fixed frame or casingof the gear, while the opposite end thereof is provided with a nut orinternally screwed socket portion 9 with which engages a screw threadedspindle 9 having, on the outer end thereof, a hand wheel g by means ofwhich the brake 9 may be tightened around the wheel or ring 6 orreleased therefrom as desired. The band 9 is provided with a frictionstrap or a series of friction blocks 9. When it is desired to lower theboat the band brake g is released from the free wheel 6 by means of thehand wheel g thereby allowing the drum d and free wheel 6 to rotate andpay out the rope 0 as the boatdescends, and,

when it is desired to hoist the boat the band brake g is tightenedaround the free wheel 6 by means of the hand wheel 9 the drum (Z beingrotated by means of the crank handles cl and pinions and gear wheels 0?.As the drum (Z rotates the'disk or wheel f is also rotated and the pawlsf thereon. run over the teeth of the free wheel 6 but, should theoperators bewashed away from, or leave their posts during the hoistingop eration the back motion of the disk f will cause the pawls f toengage the wheel 6 thereby arresting the rotation of the disk or wheel fand drum d and holding the boat.

For automatically locking the davit in place there is secured thereon aprojection h which moves over the face of the ring 7&1 through which thedavit is passed and provided on this ring 71,1 are two stop blocks orprojections b k by means of which the movement of the davit a isarrested the hole k in the projection 72, coinciding with one or otherof the holes if in the-ring h when the davit is so arrested. Inengagement with the hole 71; in the projection h and capable 'ofdropping by gravity into engagement with one of the said holes 7?, isthe locking pin 6 which is connected by means of the rod 2' with apivoted hand lever i in such manner that it may tall automatically intoengagement with one of: the holes it, and may be raised out ofengagement by means of the hand lever 2' The davit a made at the footthereof with a socket within which is a spring j whose one end issecured by a project-ion to the socket and whose other end is secured toa fixed base part extending into the socket j and fitting tightlytherein in such manner as to prevent the admission of water to thespring. Extending upward from the base portion is a central pin whoseupper end is fitted into a bearing hole made in the upper end of thesocket j and located between the upper end of this pin 70 and the davitis a washer 71: for taking up wear. The torsional action of the spring3' checks and resists the movement of the davit as itswings therebypreventing the snug h violent-1y jarring against the stops (b 72, whichlatter may also, if desired, be provided with rubber cushions.

The pulley block 0 is provided, for engagement with the sling m, with ahook at having a pivoted nose part a which, on the load being taken oilthe hook, automatically opens and so disengages the hook, the pivotednose part a being held closed, when so desired, by means of a chain orthe like M. In order to prevent the boat swinging outward, undercentrifugal force, on the davit being turned around, the hook part 0 ispro vided, with which the gunwale of the boat can be brought intoengagement and then held by tightening up the rope 0.

If so desired the hoisting gear may, instead o't being operated by hand,be operated by means of steam, hydraulic, electric or other power, asuitable motor being mounted on, or being located in any convenientposition clear of the davit. Instead of the spring 7" at the foot of thedavit, means, consisting of pawl and ratchet or equivalent mechanism,might, if desired, be provided for preventing the davit swingingbackward when being moved from the inboard to the outboard position andvice versa. The davit may, if desired, be arranged between two boats sothat, as desired, one or other of the boats can be manipulated.

Having now fully described my invention what I claim and desire tosecure by Letters Patent is 1. A ships davit comprising, in combination,a single davit turning upon a vertical axis and from which the boat isslung centrally by a single rope, winding gear on the davit for loweringand raising the boat, means for locking the davit in the outmostlowering position and also in the inboard position and spring means atthe bottom of the davit for checking the movement of the davit.

2. A ships davit comprising, in combination, a single davit turning upona vertical axis and from which the boat is slung centrally by a singlerope, winding gear on the davit for lowering and raising the boat, meansfor locking the davit in the outmost lowering position and also in theinboard position, a socket in the bottom of the davit and spring meansin the socket for checking the movement of the davit.

3. A ships davit comprising, in combination, a single davit turning upona vertical axis and from which the boat is slung centrally by a singlerope, winding gear on the davit for lowering and raising the boat, meansfor locking the davit in the outmost lowering position and also in theinboard position, a socket in the bottom of the davit, a fixed base withprojecting pin entering said socket and a spring interposed between thebase and the socket so as to check the movement of the davit.

4. A ships davit comprising, in combination, a single davit turning upona vertical axis and from which the boat is slung centrally by a singlerope, winding gear on the davit for lowering and raising the boat, meansfor automatically locking the davit in the outmost lowering position andalso in the inboard position, a socket in the bottom of the davit, afixed base with vertically projecting pin, a projection on the base, aprojection in the socket, and a spiral spring wound around said pin andwhose ends bear against said projections.

5. A ships davit, comprising, in combination, a single davit turningupon a vertical axis and from which the boat is slung centrally by asingle rope, winding gear on the davit for lowering and raising theboat, means for automatically locking the davit in the outmost loweringposition and also in the inboard position, a socket in the bottom of thedavit, a fixed base with a vertically projecting pin, a projection onthe base, a projection in the socket, a spiral spring wound around saidpin and whose ends bear against said projections, and a washerinterposed between said spring and the upper end of the socket.

6. A ships davit comprising, in combination, a single davit turning upona vertical axis and from which the boat is slung centrally by a singlerope said davit being stepped at a lower deck of the ship and passing upthrough the boat deck of the ship, means located in the boat deck forlocking the davit in the outmost lowering position and also in theinboard position and spring means at the bottom of the davit forchecking the movement of the same.

7. A ships davit comprising, in combination, a single davit turning upona vertical axis and from which the boat is slung centrally by a singlerope connected thereto in the longitudinal center line thereof said andthe socket so as to check the movement of the davit.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN GRAHAM.

davit being stepped at a lower deck of the ship and passing up throughthe boat deck of the ship means located in the boat deck for locking thedavit in the outmostlowering position and also in the inboard position,a socket in the bottom of the davit, a fixed base with projecting pinentering said socket and a spring interposed between the baseW'itnesses:

HUGH D. FITZIATRICK, WILLIAM G. CARRUTHERS.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

